Yes, I know (some) British would disagree, but they're wrong. The part you quoted below about Swan stated that "his filament had low resistance, thus needing heavy copper wires to supply it". That is the key reason that Swan and everyone but Edison completely failed to REALLY invent an incandescent light that didn't burn out right away. And not to mention that even if it somehow didn't burn out, it would still be useless for a home owner because of the high current needed to operate it.
In the same Wikipedia article you quoted it said that Paul Israel concluded that the high resistance filament was the key invention, and why Edison's 22 predecessors failed. And later in the article is said that the US Patent Office thought about invalidating the patent, but concluded that the high resistance filament was a valid patent claim. So I repeat: What is the point of inventing non-working, non-practical light bulbs? None! They are all failures, not inventions. Edison himself made dozens of light bulbs that were utter failures. Such as platinum filaments, many of which required elaborate thermal cutout mechanisms inside the bulb to shut off power as the platinum reached melting temperature. Those weren't valid light bulbs any more than Swan's were. They were failed experiments, not real inventions. Edison would not have the nerve to claim a failed experiment was a valid invention, as some historians now do. Did any of you guys ever read all the detailed accounts of Edison working on the light bulb? As an electrical engineer, I was fascinated. Scientists of the day said that Edison's attempt to "subdivide the light" was against the laws of physics. They were thinking in terms of old-fashioned arc lights that used high current, and thus had to be wired in series. Only Edison understood that to succeed he needed high resistance lights, which allowed them to be wired in parallel. Imagine if there was no Edison, and most lights in your house or on your whole street had to be wired in series! Edison was so far beyond others in the field that there is no comparison. Jim On Jul 3, 2011, at 9:29 PM, Bill Burns wrote: > On 7/3/2011 8:38 PM, Jim Nichol wrote: >> I strongly disagree. Yes, Google will tell you that many others worked on >> the light bulb. But those stories all conclude that none of them were >> practical. Edison's contribution was not only that he invented the power >> plant, but more importantly, he invented the first practical incandescent >> bulb. > > The British would disagree: > > "In 1850 Swan began working on a light bulb using carbonized paper filaments > in an evacuated glass bulb. By 1860 he was able to demonstrate a working > device, and obtained a British patent covering a partial vacuum, carbon > filament incandescent lamp. However, the lack of a good vacuum and an > adequate electric source resulted in an inefficient bulb with a short > lifetime. > > "Fifteen years later, in 1875, Swan returned to consider the problem of the > light bulb with the aid of a better vacuum and a carbonized thread as a > filament. The most significant feature of Swan's improved lamp was that there > was little residual oxygen in the vacuum tube to ignite the filament, thus > allowing the filament to glow almost white-hot without catching fire. > However, his filament had low resistance, thus needing heavy copper wires to > supply it.[7] > > "Swan received a British patent for his device in 1878, about a year before > Thomas Edison. > > "In America, Edison had been working on copies of the original light bulb > patented by Swan, trying to make them more efficient. Though Swan had beaten > him to this goal, Edison obtained patents in America for a fairly direct copy > of the Swan light, and started an advertising campaign which claimed that he > was the real inventor. Swan, who was less interested in making money from the > invention, agreed that Edison could sell the lights in America while he > retained the rights in Britain." > > http://en.wikipedia.org/wiki/Joseph_Swan > > -- > Bill Burns > Long Island NY USA > http://ftldesign.com > _______________________________________________ > Phono-L mailing list > http://phono-l.oldcrank.org _______________________________________________ Phono-L mailing list http://phono-l.oldcrank.org
